. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . Dynamo Model Riak is a highly available, proprietary key-value structured storage system or a distributed data store. It has properties of both databases and distributed hash tables (DHTs). It is not directly exposed as a web service, but is used to power parts of other Amazon Web Services such as Amazon S3.
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . Dynamo Model Riak is a highly available, proprietary key-value structured storage system or a distributed data store. It has properties of both databases and distributed hash tables (DHTs). It is not directly exposed as a web service, but is used to power parts of other Amazon Web Services such as Amazon S3.
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . Dynamo Model Riak is a highly available, proprietary key-value structured storage system or a distributed data store. It has properties of both databases and distributed hash tables (DHTs). It is not directly exposed as a web service, but is used to power parts of other Amazon Web Services such as Amazon S3.
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . Dynamo Model Riak is a highly available, proprietary key-value structured storage system or a distributed data store. It has properties of both databases and distributed hash tables (DHTs). It is not directly exposed as a web service, but is used to power parts of other Amazon Web Services such as Amazon S3.
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . Dynamo Model Riak is a highly available, proprietary key-value structured storage system or a distributed data store. It has properties of both databases and distributed hash tables (DHTs). It is not directly exposed as a web service, but is used to power parts of other Amazon Web Services such as Amazon S3. Implementations Apache Cassandra Project Voldemort Riak Amazon DynamoDB
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . CAP theorem Consistent, writes are atomic and all subsequent requests retrieve the new value Available, the database will always return a value as long as a single server is running Partition Tolerant, the system will still function even if server communication is temporarily lost—that is, a network partition
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . CAP theorem Consistent, writes are atomic and all subsequent requests retrieve the new value Available, the database will always return a value as long as a single server is running Partition Tolerant, the system will still function even if server communication is temporarily lost—that is, a network partition You can have only two at once.
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . Eventual Consistency Distributed databases must be partition tolerant, so the choice between availability and consistency can be difficult. The real world is eventually consistent and works (mostly) fine *Eventual* doesn’t mean minutes, days, or even seconds in non-failure cases DNS, HTTP with Expires: header How you model the real world matters!
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . The tldr; version MapReduce is a framework for processing embarrassingly parallel problems across huge datasets using a large number of computers (nodes), collectively referred to as a cluster (if all nodes are on the same local network and use similar hardware) or a grid (if the nodes are shared across geographically and administratively distributed systems, and use more heterogenous hardware). Computational processing can occur on data stored either in a filesystem (unstructured) or in a database (structured). MapReduce can take advantage of locality of data, processing data on or near the storage assets to decrease transmission of data.
. .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . .. . . . .. . . . . .. . . . .. . . . . .. . . . .. . . . .. . . . Why use Riak Flexible APIs Riak is equipped with fully-featured HTTP and Protocol Buffers APIs, with support for both of these transports in all of our supported client libraries. You can also write your own client layer to wrap our APIs if your use case or preference calls for it.